Advances in Traditional Chinese Medicine for Managing Diminished Ovarian Reserve: Mechanisms and Clinical Insights

Foreword

Diminished Ovarian Reserve (DOR) is a clinical syndrome characterised by a decrease in the number and quality of ovarian follicles, with pathological features such as reduced levels of anti-Müllerian hormone (AMH), reduced sinusoidal follicle counts (AFC), and elevated levels of follicle-stimulating hormone (FSH), among other biomarker abnormalities.¹ Epidemiological survey data show that the prevalence of DOR has increased significantly from 19% in 2004 to 26% in 2014, and now accounts for approximately 20% of ovarian-related diseases in women, with a significant trend towards younger age.^2–4 This disease not only directly leads to decreased fertility but also may progress to Premature Ovarian Failure (POF) within 1–6 years if not intervened in a timely manner, posing a dual threat to women’s reproductive and psychological health.⁴

Modern medicine mainly uses hormone replacement therapy (HRT), dehydroepiandrosterone (DHEA) and growth hormone as therapies.⁵ Although these therapies temporarily improve hormone levels and ovarian responsiveness, long-term application may induce serious complications such as increased risk of breast cancer and endometrial hyperplasia.⁶ Although emerging coenzyme Q10 interventions have shown potential in improving embryo quality and clinical pregnancy rates, their long-term efficacy and safety still need to be validated in large-scale cohort studies.^7,8 Two key limitations of existing treatment protocols prevail: first, there is an efficacy discrepancy between symptomatic relief and improvement in ovarian function; and second, the system for monitoring the safety of long-term drug use has not yet been developed.

Against this background, the advantages of Chinese medicine’s overall regulation have gradually come to the fore. Based on the theory of “the kidney is the master of reproduction”, TCM interventions have shown unique efficacy in improving AMH levels and increasing the natural pregnancy rate through multi-targeted regulation (eg, hypothalamus-pituitary-ovary axis, mitochondrial function, and oxidative stress pathway, etc.).⁹ However, it should be noted that the safety of TCM treatment still needs to be systematically evaluated: for example, some heavy metal-containing minerals may cause accumulation toxicity (eg, the free mercury content of cinnabar can reach 27–354 μg/g, and the soluble mercury content can reach 8–17 μg/g),¹⁰ and the phytopharmaceutical-chemical interactions may affect the hepatic enzyme activities (CYP3A4 inhibition rate can reach 41%).¹¹ In this study, we systematically reviewed the mechanism studies (involving 12 signalling pathways, including PI3K/AKT) and clinical evidence on the treatment of DOR by TCM in the past ten years, focusing on the strategy of efficacy–safety balance, with a view to providing theoretical basis for the establishment of a risk prevention and control system combining traditional Chinese and Western medicines and the development of new Chinese medicinal preparations. The specific mechanism of action is shown in Figure 1.

Figure 1 Shows the mechanism of traditional Chinese medicine in the treatment of diminished ovarian reserve (DOR) through multiple pathways such as anti-oxidation, immune regulation, PI3K / AKT signaling pathway, apoptosis autophagy, miRNA regulation and reproductive hormone balance.

Traditional Chinese Medicine for DOR

Traditional Chinese Medicines and Their Monomer Components

In the study of treating DOR, red ginseng and Epimedium and their monomer active components have demonstrated unique pharmacological activities and therapeutic potentials. Red ginseng significantly inhibits the phosphorylation expression of PI3K/AKT signalling pathway, promotes follicular development and improves serum hormone profiles through the mechanism of benefiting qi and tonifying the kidney and filling in the essence, and its property of elevating the levels of AMH and GnRH has a dual improvement effect on the function of ovarian reserve.¹² Epimedium, on the other hand, effectively relieves clinical symptoms of DOR patients through the biological effects of spleen and kidney dual tonic, and excels in increasing the proportion of high-quality embryos and normal fertilisation rate, ultimately achieving systematic optimisation of the effects of fertility support.¹³

Modern pharmacological studies have revealed that the active ingredients of many Chinese medicines have multi-target regulatory properties: paeoniflorin restores the function of estradiol synthesis in ovarian granulosa cells through the activation mechanism of FSHR/cAMP/PKA/CREB signaling pathway, increasing the number of sinus follicles by 42% and luteal formation rate by 29% in a mouse model;¹⁴ Epimedium glycoside has a bidirectional regulation of granulosa cells, significantly elevating estradiol secretion and cell proliferation rate at a concentration of 5 μg/L concentration significantly elevated estradiol secretion and cell proliferation rate;¹⁵ total flavonoids of Cuscuta sinensis elevated ovarian index through FSH-cAMP/PKA pathway activation;¹⁶ serpentin reduced the levels of inflammatory factors IL-1β and TNF-α while increasing SOD activity through Nrf2/HO-1/NLRP3 pathway regulation;¹⁷ dandelion extract, on the other hand, significantly increased the number of mature oocytes and the rate of high-quality embryos.¹⁸ These studies provide a scientific basis for the synergistic treatment of DOR with multiple components of traditional Chinese medicine.

Chinese Medicine Pairs

Chinese medicine pairs in the prevention and treatment of DOR have focused on two groups of typical pairings: Cuscuta chinensis–Sambucus spp. and Xianmao–Epimedium. He Yan’s team demonstrated that the Cuscuta chinensis–Mulberry parasitic vine pair has the dual effects of nourishing the liver and kidney and protecting the foetal element. Its mechanism of action involves regulating the balance of endometrial matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-3 (TIMP-3) expression, effectively improving the endometrial tolerance of the model mice, and the experiments observed that the animals’ physical signs improved significantly (moist fur, increased vitality, body weight gain), and uterine tissues showed a healthy, reddish state and increased elasticity, and the pairing can significantly enhance anti-müllerian hormone (AH) and improve the quality of the fetus. This formula can significantly increase the level of anti-Müllerian hormone (AMH) and the balance of sex hormones, thus enhancing the ovarian reserve function.¹⁹ Xie Ying et al further found that Cuscuta sinensis alone could achieve bidirectional regulation of hormone levels by modulating lipid metabolism-related signalling pathways and atherosclerotic pathways, providing a new molecular mechanism explanation for the improvement of ovarian reserve.²⁰

In the study of the Xianmao–Epimedium pair, Hu Changrong’s team used network pharmacology technology to analyse its action network, and found that its main active ingredients may cover quercetin, lignans, kaempferol and β-sitosterol, etc., and the target network involves key molecules such as AKT1, IL-6, TP53, VEGFA and CASP3. In-depth analyses showed that these components may exert therapeutic effects by modulating complex biological processes such as cancer-related pathways, AGE-RAGE signalling, IL-17 inflammatory pathway, PI3K-AKT survival pathway, apoptotic program, HIF-1 hypoxia-responsive pathway and NF-κB inflammatory network.²¹

Comprehensively, existing studies have shown that TCM treatment of DOR exhibits multidimensional regulatory advantages: on the one hand, it improves ovarian function through specific signalling pathway activation, hormone secretion regulation and cellular damage repair; on the other hand, single herbs (eg, red ginseng, Epimedium) and classical pairs of herbs significantly enhance ovarian reserve capacity through multi-targeted synergistic effects. These research results not only systematically explain the mechanism of DOR treatment by TCM but also provide a scientific basis for clinical practice and a direction for innovative drug research and development, fully demonstrating the unique value of TCM in reproductive health (Table 1).

Table 1 Summary of Traditional Chinese Medicine Treatment Strategies for DOR

Traditional Chinese Medicine Prescriptions for the Treatment of DOR

At present, there are 14 traditional Chinese medicine prescriptions for the treatment of DOR, most of which are derived from ancient books such as “The Essentials of the Golden Quarter”, “The Encyclopaedia of Jingyue”, and “Fu Qingzhu’s Women’s Science”, etc., which have been clinically tested for thousands of years, with remarkable therapeutic efficacy, and have been followed by successive generations of medical doctors to the present day. Through the TCM dialectic typing of DOR, traditional Chinese medicine prescriptions for DOR can be classified into the category of nourishing the liver and kidneys, invigorating blood circulation and removing blood stasis, and other categories.

Nourishing the Liver and Kidneys

Traditional Chinese medicine compound formulas used for the treatment of DOR that nourish the liver and kidneys include: Six-flavoured Dihuang Pill, Zuo Gui Wan, Yulin Zhu, Yu Gui Wan, Ding Jing Tang, Nourishing Essence and Planting Jade Tang, and Gui Kidney Pill. Gao Ting et al showed that Liu Wei Di Huang Wan²² could effectively regulate the estrous cycle in mice, significantly elevate serum hormone levels and promote follicular development through the triple mechanism of anti-oxidative stress, inhibition of inflammatory response and immunomodulation, which was ultimately manifested as a dual improvement in the number of litters and survival rate of pups. Clinical data of Zuo Gui Wan^23–25 showed that it could increase the acquisition rate of IVF-ET effective embryonic cycles to 57.6%, and its mechanism of action involves: ①regulating the TLR4/NF-κBp65 signalling pathway, and down-regulating the inflammatory factors, such as IL-1β, TNF-α, etc.; ② decreasing the expression of key proteins, such as TLR4, NF-κBp65, MyD88, and p-I κB-α, etc.; ③significantly improving ovarian/uterine indices. Significantly improved ovarian/uterine index, elevated mean sinus follicle count (AFC) and reduced follicular atresia. Yulin Zhu,^26,27 through the regulation of PI3K/AKT apoptosis signalling pathway, achieved: ① reversal of the abnormally high expression of apoptosis markers such as Caspase-3/9, BAX and cytochrome C; ② reduction of TUNEL positivity and apoptosis of granulosa cells in ovarian tissues; and ③simultaneous improvement of the abnormal mitochondrial function, which was clinically manifested by the restoration of the menstrual cycle and the normalisation of hormone levels. Right Angelica Pill^28,29 significantly optimised the diameter of sinus follicle development and ovarian volume while elevating serum E2 levels. Clinical observations of Dingjing Tang^30,31 showed that it could effectively regulate the regularity of the menstrual cycle and significantly increase the AFC value. Nourishing Essence and Planting Jade Soup^32,33 achieves ovarian cortical structural repair through dual regulatory mechanisms: ①epigenetic modification of ovarian RNA-m6A; ②activation of the PI3K/AKT signalling pathway, as evidenced by an increase in the number of growing follicles and elevation of uterine/ovarian wet weight. By inhibiting autophagy in ovarian tissue, Gui Ren Wan³⁴ can improve ovarian morphology and serum hormone levels, increase primordial follicles and growing follicles, reduce atretic follicles, and then improve ovarian reserve function.

Modern pharmacological studies reveal that the above formulae act on the hypothalamic-pituitary-ovarian axis through a multidimensional mechanism of action – including antioxidant damage, inhibition of inflammatory factors, modulation of key signalling pathways and maintenance of ovarian microenvironmental homeostasis - to ultimately achieve an overall improvement in ovarian reserve function.

Promoting Blood Circulation and Eliminating Blood Stasis

Clinical studies have confirmed the significant efficacy of blood circulation and elimination of blood stasis Chinese herbal compounds in DOR, which mainly include the three classic formulas, namely, Haifuyuyuyuyu Tang, Guizhi Poria Pill, and Wenjing Tang. Cai Caolei’s team showed³⁵ that Haifu yuyu tang could effectively improve clinical symptoms such as abnormal menstrual flow and significantly increase endometrial thickness in patients with DOR. Several evidence-based studies^36–38 indicated that Wenjing Tang, through a multi-targeted mechanism of action, not only increased ovarian volume and sinus follicle count (AFC) but also optimised endometrial tolerance indexes and improved endometrial and subendometrial blood perfusion parameters. In addition, the formula demonstrated significant advantages in improving ovulation success, embryo implantation rate and clinical pregnancy rate.

Modern pharmacological studies have revealed that this formula can effectively enhance the ovarian reserve function of DOR patients by regulating the function of hypothalamic-pituitary-ovarian axis, improving ovarian microcirculation, and inhibiting follicular closure. The synergistic mechanism of its multi-components not only improves reproductive endocrine indexes but also enhances the physiological functions of the female reproductive system as a whole, providing DOR patients with a therapeutic solution with both efficacy and safety.

Others

In addition to the prescriptions described in the previous section, traditional Chinese medicine prescriptions commonly used in the treatment of DOR include Angelica sinensis and Paeonia lactiflora powder, Zhi Bai Di Huang Wan, Ding Kun Dan, and Kun Tai capsule (derived from Huanglian and Agaricus soup). Several studies have shown that these compound formulas have significant efficacy in improving clinical symptoms and reproductive outcomes in patients with DOR through a multi-targeted mechanism of action.

As a classic gynecological formula, the efficacy of Angelica sinensis and Paeonia lactiflora powder^39–43 is reflected in the following: (1) morphological improvement of reproductive organs: significantly increase ovarian volume, improve ovarian index, promote the number of growing follicles and mature follicles, synchronously reduce the number of atretic follicles, optimize the structure of the ovarian stroma, and reduce the degree of fibrosis of the mesenchyme; (2) endometrial remodeling: induce endometrial lining to form a wave-like structure, and regulate the arrangement of uterine glandular epithelial cells and myometrial fibroblasts by regulating the endometrial gland. Endometrial remodelling: induces the endometrium to form a wave-like structure, and increases the density of glands and the distribution of blood vessels by regulating the arrangement of epithelial cells and the direction of myometrial fibres; ③Reproductive function enhancement: clinical data have shown that it can increase the pregnancy rate and the average number of embryos implanted; ④Molecular mechanism: by regulating the function of hypothalamus-pituitary-ovary axis, activating the PI3K/AKT/FOXO3a signaling pathway, modulating the TGF-β1/Smads signaling, upregulating the levels of serum oestradiol (E2), progesterone (P) levels, and promotes uterine tissue leukaemia inhibitory factor (LIF), integrin αvβ3 protein and endometrial glycoprotein (glycodelin) mRNA expression.

The intervention mechanisms of Zhi Bai Di Huang Wan^44–47 include: (i) immune regulation: correcting the balance of Th1/Th2 cells; (ii) haemodynamic improvement: lowering the uterine arterial resistance index (RI) and pulsatility index (PI); (iii) enhancement of the reproductive system function: increasing the thickness of the uterine endometrium, optimizing the volume of the ovaries and the state of blood supply, and enhancing the rate of menstrual resumption, the rate of spontaneous pregnancy, and the success rate of assisted reproduction techniques; and (iv) endocrine regulation: effectively improving serum leukemia inhibiting factor (LIF) and integrin αvβ3 protein and glycodelin. Endocrine regulation: effectively improve serum follicle stimulating hormone (FSH), luteinising hormone (LH) and other hormone levels.

Dingkundan^48–52 works through a dual mechanism: (i) signalling pathway regulation: inhibiting the over-activation of PI3K/AKT/mTOR pathway; (ii) gene expression regulation: down-regulating the expression level of specific mRNA. Clinical data show that it can significantly improve the regularity of menstrual cycle, increase the number of eggs, the rate of quality eggs, the rate of fertilisation and the rate of natural pregnancy.

The effects of Kuntai capsule (Huanglian Ajiao Tang)^53–73 include: (1) neuroendocrine regulation: improve the ovarian reserve function through the homeostatic regulation of H-P-O axis; (2) apoptosis regulation: balance the Bcl-2/Bax protein ratio; (3) improvement of the reproductive outcome: significantly increase the level of E2 of single mature follicle in the day of HCG, increase the number of embryos that can be transplanted, and at the same time effectively alleviate the endocrine disorders related clinical symptoms.

Comprehensive analysis showed that traditional Chinese medicine compound treatment of DOR has multi-dimensional intervention advantages (Table 1), which are mainly reflected in: improvement of clinical symptoms; significant optimisation of reproductive endocrine regulation; enhancement of fertility and clinical pregnancy rate; and remodelling of the uterine microenvironment. The mechanism of action involves multiple biological processes such as signalling pathway regulation, gene expression modification, and apoptosis balance, reflecting the therapeutic characteristics of TCM holistic regulation. See Table 2.

Table 2 Summary of Traditional Chinese Medicine Prescription Strategies for DOR

Self-Drafted Prescriptions for DOR

Self-designed prescription (also known as empirical prescription) is a special formula that is scientifically formulated by a Chinese medicine practitioner based on clinical experience and the theory of identification and treatment of Chinese medicine, selecting local herbs and determining the dosage through the four diagnostic consultations, and following the principle of the combination of the ruler, ministers and auxiliaries,⁷⁴ according to the characteristics of the patient’s individualised symptoms. In the clinical treatment of early-onset ovarian insufficiency (DOR), the common self-proposed formulas are mainly based on the theory of “the kidney is the master of reproduction” and can be classified into four categories according to the core mechanism of action: tonifying the kidney to fill the essence, tonifying the kidney to nourish yin, tonifying the kidney to activate blood circulation, and tonifying the kidney to regulate menstruation, reflecting the Chinese medicine concept of treating the same disease with the same treatment for the same condition and treating the same disease with different treatment for different conditions.

Replenishing the Kidney and Filling the Essence

In Chinese medicine theory, the therapy of replenishing the kidney and filling the essence, which is centred on the axis of “kidney essence - tianjie - chongren” as the core treatment for improving reproductive function, is mainly aimed at optimizing reproductive function by targeting and regulating the key signalling pathway of follicular development. Experimental studies have shown that the Rejuvenation Formula^75,76 significantly inhibited apoptosis and primary follicular atresia by activating the AKT signalling pathway, and improved the serum hormone level of the VCD-induced diminished ovarian reserve (DOR) rat model, while the Kidney Replenishing and Ovulation Promoting Formula⁷⁷ synergistically acted through the PI3K/AKT/mTOR, Bax/CytC/Caspases-3 and Nrf2/ARE multiple pathways. /ARE multi-pathway synergism, which not only improved the motility cycle disorder but also increased the ovarian/uterine index, increased the number of primordial follicles, sinus follicles and corpus luteum while decreasing the counts of secondary follicles and atretic follicles, and promoted the thickening of endometrial lining and the development of glands; Jikgui Yichong formula, through regulating the PI3K/AKT pathway, significantly regulated follicle number and distribution while improving the weight factor of the ovaries and the morphology of the tissues.⁷⁸ Kidney and Blood Formula focuses on activating the PI3K/AKT/mTOR signalling pathway to increase the number of mature follicles and the total number of follicles;⁵⁶ and Qi Zi Yi Ren Li Chong Tang effectively reduces granulosa cell apoptosis and protects the primordial follicular reserve while improving ovarian histological morphology and serum hormone levels through the transcriptional regulation of the PLA2G4A gene mediated by miRNA29-a.⁷⁹ Although these combinations have different targets, they all focus on regulating the dynamic balance of follicle survival and maturation, and ultimately achieve the overall improvement of ovarian reserve function.

Kidney Tonifying and Yin Nourishing

In the system of kidney tonifying and essence filling therapy, which is based on nourishing yin and lowering fire in Chinese medicine theory, Purple Sophora formula significantly increased the number of follicles at all levels and luteal counts, and simultaneously reduced the proportion of atretic follicles and the percentage of TUNEL-positive ovarian cells by regulating the secretion of gonadotropins of hypothalamus-pituitary-ovary axis (HPOA) and inhibiting granulocyte apoptosis mediated by the PI3K/AKT pathway.⁸⁰ In addition, by regulating the PTEN/PI3K/AKT signalling pathway, Yi Kidney Meridian Regulating Formula can effectively improve the disorders of the estrous cycle, enhance the gonadotropic index, and increase the number of follicles at all levels of growth in the ovary;⁸¹ and by regulating the function of the neuroendocrine system, Zi Gui Nian Zhen Capsules can improve the function of the ovary and the quality of the oocyte, and at the same time, significantly enhance the tolerance of the uterus lining and the proliferation of the activity.⁸² Although the above prescriptions have different mechanisms of action, they all reflect the principle of nourishing yin and reducing fire, and achieve the reconstruction of the dynamic balance of hormone levels by regulating the function of the hypothalamic-pituitary-ovarian axis (HPOA), and synergistically improve the ovarian microenvironment and reproductive endocrine status.

Nourishing the Kidney and Activating Blood

Based on the theory of “kidney deficiency and blood stasis”, Chinese medicine activates blood and removes blood stasis, which is an important means to regulate follicular development by improving ovarian microcirculation and antioxidant capacity. It was found that Baoqing granules significantly improved ovarian wet weight and index, increased the number of dominant follicles and granulosa cell layers, and simultaneously improved serum hormone levels by down-regulating the expression of Bax protein and up-regulating the expression of Bcl-2 and VEGF proteins;⁸³ He’s Nest Nourishing Formula effectively promoted follicular growth, increased the number of corpus luteum and ovulated eggs through the modulation of the ROS/JNK/p53 signalling pathway and optimized the serum hormone profile.⁸⁴ The He’s Nest Nourishing Formula effectively promotes follicular development, increases the number of corpus luteum and ovulatory oocytes, and optimises serum hormone profiles;^84,85 Zigui Wujing Capsules enhance endometrium-specific proliferative capacity through neuroendocrine regulation;^78,82 and Yulin Formula targets the downstream molecules of the wnt4 pathway to significantly enhance the quality and quantity of follicular development.⁸⁶ Although the intervention pathways of each formula are different, they all focus on improving ovarian blood flow and perfusion and apoptosis regulation, restoring the microenvironment of follicular development through multi-target synergism, reflecting the integrative therapeutic feature of Chinese medicine “activating blood circulation and promoting collaterals, nourishing kidneys and nourishing the ovaries”.

Kidney Tonic and Menstruation Regulator

Under the framework of TCM menstruation regulator and fertility promoter theory, the characteristic therapies aiming at restoring the reproductive endocrine rhythms are mainly embodied in the following: Kidney tonic and fertility promoter formula achieves the prevention and treatment of DOR through a dual regulating mechanism, which regulates the secretion of gonadal hormones of the hypothalamic-pituitary-ovarian-adrenal (HPOA) axis, and exerts a reproduction protective effect by protecting the granulosa cells of the ovary from the damage of the pyroptosis pathway;⁸⁷ Qi Yue tea, on the other hand, targeted the ovarian apoptosis regulation mechanism, by specifically reducing the expression level of pro-apoptotic factor Bax in ovarian tissues, significantly elevating the ovarian body mass index and anti-Müllerian hormone (AMH) values, and synchronously improving the balance of serum reproductive hormone profiles;⁸⁸ Kidney tonifying and blood-healing formula innovatively acted on the angiogenesis regulation system by promoting the secretion of vascular endothelial growth factor (VEGF) and its receptors, flt-1, kdc, flt-1, flt-1, flt-1, and kdc. By promoting the expression of vascular endothelial growth factor (VEGF) and its receptors, flt-1 and kdr protein, it enhances the ovarian blood supply, and at the same time, by regulating the dynamic balance of the Bcl-2 family of proteins (activation of anti-apoptotic Bcl-2/inhibition of pro-apoptotic Bax), it achieves the enhancement of the ovarian index and optimisation of serum hormone levels.⁸⁹ All of the above therapies are adhering to the essence of the theory of “meridian-blood homology”, and through the core intervention strategy of qi and blood harmonisation, they can systematically improve ovarian physiological function indexes and the coordination of endocrine rhythms.

In summary, Chinese medicine has developed the above four types of self-proposed formulas based on the theory of “the kidney is the master of reproduction” in the treatment of early-onset ovarian insufficiency (DOR). Although the target points of each type of formula are different (eg AKT pathway, ROS/JNK/p53 pathway, VEGF expression, etc.), they all embody the therapeutic characteristics of multi-target synergism, and through the regulation of follicular development, inhibition of apoptosis of granulosa cells, and improvement of the microenvironment of the ovary, they ultimately achieve the enhancement of the reserve function of the ovary, optimization of hormone levels, and repair of endometrial lining, which demonstrates the discriminative thinking of Chinese medicine and its advantage of holistic regulation of “treating different diseases together”. This demonstrates the advantages of TCM’s “treating different diseases at the same time” and holistic regulation. See Table 3 for details.

Table 3 Summary of Self-drafted TCM Prescription Strategies for DOR

Acupuncture for DOR

Acupuncture therapy, as one of the common methods of external treatment in Chinese medicine, plays a unique role in regulating endocrine function, promoting ovulation, regulating immunity, improving ovarian reserve function and microenvironment and other gynecological disorders, and there are various dialectical methods of acupuncture treatment for DOR, including internal organs dialectics, meridian dialectics and menstrual cycle dialectics. On the basis of ordinary acupuncture, for the research and treatment of DOR, unique methods such as 13 needles for regulating menstruation and promoting pregnancy and acupuncture sequential therapy have been developed, and electro-acupuncture therapy has been formed by combining with modern science and technology in order to continuously develop the therapeutic means of acupuncture.

General Acupuncture

Acupuncture has demonstrated significant effects in the treatment of DOR and IVF-ET. It was found that acupuncture on Guanyuan, Sanyinjiao, Sea of Blood, Taixi, and Baihui could improve the hormone levels and clinical symptoms of DOR patients, especially for patients with kidney deficiency and blood stasis type.⁹⁰ For patients with kidney deficiency and liver stasis type, acupuncture points such as Guanyuan, Uterus, and Sanyinjiao not only improved the clinical symptoms in TCM but also enhanced the ovarian reserve function indexes, including AMH level, AFC, ovarian size, and blood perfusion parameters.⁹¹ During IVF-ET, acupuncture can increase embryo implantation rates and improve pregnancy outcomes.⁹² Further studies have shown that acupuncture can promote egg development in patients with DOR by affecting the expression of specific factors in follicular fluid, such as ICAM-1 and COX-2, thereby increasing the in vitro fertilisation rate and improving the outcome of IVF-ET.⁹³

In addition, acupuncture therapy can effectively improve the symptoms and fertility indicators of patients with diminished ovarian reserve, as well as alleviate related gynaecological problems. Acupuncture on the ovaries, uterus, and tai chong can regulate the blood flow parameters of the ovaries and uterus, increase the number of basal sinus follicles and the volume of the ovaries, alleviate local symptoms, and promote the recovery of ovarian function.⁹⁴ Zhang Junxin⁹⁵ and others showed that acupuncture treatment given to patients with DOR can effectively improve patients’ clinical symptoms in Chinese medicine, improve basal sex hormone levels and ovarian function, and have a high overall clinical effectiveness rate. Moreover, acupuncture can also effectively relieve dysmenorrhoea symptoms and reduce chocolate cyst masses in DOR patients.⁹⁶ For patients with infertility, especially due to DOR, acupuncture on both ventral and dorsal sets of acupoints has been shown to decrease FSH levels, increase the number of AFCs, elevate the level of AMH, reduce anxiety symptoms, and increase the number of available embryos in ovulation-promoting cycles with a good safety profile.⁹⁷

As for basic animal research, acupuncture may inhibit NLRP3 mRNA expression through the Nrf2/HO-1 signalling pathway, thereby inhibiting the inflammatory response, which in turn restores the motility cycle in DOR model rats and effectively regulates rat sex hormone levels.⁹⁸ Acupuncture can also clear the inflammatory response of inflammatory factors to the thyroid and ovary by lowering the levels of IL-17A and IL-6 in rats in order to increase the levels of FSH, LH, GnRH, and AMH, repair ovarian tissues, and activate the ovarian reserve function.⁹⁹ In addition, Dong Wenjia¹⁰⁰ et al showed that acupuncture points such as Vital Gate, Guanyuan, and Ren Yu could increase bilateral ovarian weight, increase ovarian index, significantly reduce the number of atretic follicles, and improve ovarian reserve function in DOR rats.

Acupuncture effectively improves the symptoms and quality of life of patients with diminished ovarian reserve function by regulating the PI3K/AKT/mTOR signalling pathway, increasing the number of FSH receptors and adjusting the expression of anti-apoptotic and pro-apoptotic proteins,¹⁰¹ and acupuncture treatment at specific acupoints such as Guanyuan and Sanyinjiao points showed good results and safety.

Electroacupuncture

Electroacupuncture therapy is a kind of acupuncture method based on the needling of millimetre needles to obtain qi, applying electroacupuncture instrument to output pulsed current, and acting on the human body parts through millimetre needles to achieve the treatment of diseases.¹⁰² Through combing, the research and treatment of DOR by electroacupuncture therapy mainly include: ordinary electroacupuncture, electroacupuncture with different timing, electroacupuncture cycle therapy, and electrical stimulation of transcutaneous acupoints.

Through the use of electroacupuncture acupuncture points of the liver meridian such as Taichong, Ligou, Ququan and Qiuquan and Qiuqin can effectively improve the clinical symptoms of patients with liver-depressed DOR regulate serum hormone levels, increase the AFC, and improve the ovarian blood supply.¹⁰³ Further studies also found that electroacupuncture could significantly improve the ovarian reserve function of rats by regulating the expression of FSHR\AMHR and its downstream PI3K/AKT/FOXO3a cell signalling pathway in ovarian tissues, which was mainly manifested as: increasing the number of sinusoidal follicles in the ovary, and improving the level of peripheral blood serum reproductive endocrine hormones and the ovarian mass index, and at the same time, it could also improve the growth retardation in the offspring of DOR rats.¹⁰⁴ Different timing of electroacupuncture can also produce different effects. Yu Shudan et al found that electroacupuncture of Zhongsiao/Tianshu in rats with ovarian damage before modelling may protect ovarian reserve function by inhibiting follicular development and stabilizing AMH gene transcription and protein expression.¹⁰⁵ In addition, electroacupuncture cycle therapy may also improve ovarian function and increase the number of eggs and high-quality embryos in IVF patients, thus increasing the HCG-positive rate, embryo implantation rate, and clinical pregnancy rate.¹⁰⁶ Qin Caifang et al also found that electroacupuncture cycle therapy not only promotes the growth of endometrial thickness but also reduces the resistance to blood flow in the uterine arteries, promotes the transformation of the patient’s endometrium to A-type, and improves the tolerance of the endometrium.¹⁰⁷ Transcutaneous electrical stimulation of acupuncture points can also increase the number of eggs acquired, the number of high-quality embryos, improve serum sex hormone levels, and further improve ovarian reserve function.^108,109

Thirteen Needles for Regulating Menstruation and Promoting Pregnancy

Thirteen needles for regulating menstruation and promoting pregnancy is also one of the commonly used needles in clinical practice, which has the effect of tranquilizing the mind, regulating Chong Ren and tonifying the kidney essence. Li et al found that the use of this needle method improved serum hormone levels, increased sinus follicle counts, menstrual conditions and anxiety symptoms of patients with DOR, and had a better safety profile.¹¹⁰ Other studies have also found that the thirteen injections for regulating menstruation and promoting pregnancy can improve the number and quality of eggs and the number of available embryos, increase the number of AFC, and improve the pregnancy outcome of IVF-ET in patients with DOR.^111–114

Acupuncture Sequential Therapy

Acupuncture Sequential Therapy¹¹⁵ is based on the reproductive physiological characteristics of different times of the menstrual cycle, based on the identification of the disease, combined with the identification of the evidence, and the cycle of using different acupuncture methods corresponding to that time. By treating DOR patients with acupuncture sequential therapy, the HCG day E2 value, AFC, the number of eggs obtained, the number of fertilised eggs, the number of high-quality embryos can be increased, and also the embryo implantation rate can be increased and the cycle cancellation rate can be reduced, so as to effectively improve the ovarian reserve function of DOR patients, and then to improve the clinical pregnancy rate of in vitro fertilization-embryo transfer.¹¹⁶

Other Acupuncture Therapies

In addition, snap-needle and meridian row acupuncture belong to special other acupuncture therapies. Among them, snap-needle therapy is a method of fixing special small needles into the skin or subcutaneously for a longer period of time, and exerts its effect on the target organs by giving persistent and gentle benign stimulation to specific acupoints.¹¹⁷ Shen Jie et al found that snap-needle therapy can effectively regulate serum sex hormone levels in patients with DOR, reduce AMH levels, and improve their clinical symptoms.¹¹⁸ Puncture method is a modern medical practitioner in the ancient acupuncture method based on the combination of clinical practice created by the method of acupuncture, puncture method based on meridian identification, puncture along the blood vessels, puncture to the pain point as the centre of puncture or puncture of the compressed nerve pathway for treatment.¹¹⁹ Tang Wenlong et al found that meridian puncture may improve clinical symptoms and menstrual cycles of DOR patients by regulating the function of the hypothalamic-pituitary-ovarian axis, improving serum hormone levels, and then improving ovarian reserve function.¹²⁰

Taken together, acupuncture therapies have demonstrated significant effects in the treatment of DOR, and as a relatively safe and low-cost non-pharmacological treatment, they have demonstrated unique advantages in improving ovarian reserve function, hormone levels, assisting in fertility, and enhancing the quality of life of patients with DOR by regulating the signalling pathway, inhibiting apoptosis, and improving the blood supply to the ovary through a variety of mechanisms. In addition, these acupuncture methods provide diverse options for the treatment of DOR and demonstrate their potential for wide application in reproductive health. See Table 4.

Table 4 Summary of Acupuncture Intervention Strategies for DOR

Summary and Prospect

Traditional Chinese medicine (TCM) has demonstrated unique advantages and potentials in the treatment of ovarian reserve decline. Through evidence-based treatment, traditional Chinese medicine (TCM) is able to achieve individualised holistic management of patients, with TCM, TCM compounds, acupuncture and therapies being used as adjuncts to IVF or hormonal therapies, intervening in the disease from multiple targets and pathways to further enhance the therapeutic effect (see Figure 2 for details). Its core advantage is that it not only focuses on symptom relief but also on regulating the overall state of the body, improving serum hormone levels, improving the ovarian microenvironment, and delaying the decline of ovarian function. However, the application of TCM in the treatment of DOR still faces some challenges, such as the uncertainty of efficacy, the mechanism of action that has not been fully elucidated, and the lack of evidence support from large-scale, high-quality clinical trials. In addition, the complex composition of TCM complexes and their effects on multiple signalling pathways still need to be further explored. Future studies should focus on revealing the mechanism of action of TCM in treating DOR, especially its effects on various aspects such as PI3K/AKT/mTOR, hypothalamic-pituitary-ovarian axis (HPO axis), ovarian microcirculation, anti-oxidative stress, and immunomodulation. Meanwhile, high-quality, multicentre randomised controlled trials need to be promoted to assess the effectiveness and safety of TCM for DOR from a scientific perspective and to establish an evidence-based medical evidence system. In addition, combined Chinese and Western medicine therapy has shown unique potential and value in the treatment of DOR disease. By combining the holistic concepts and principles of evidence-based treatment in TCM with the precise diagnostic and therapeutic methods of modern medicine, TCM can not only effectively intervene for the specific etiology of DOR but also improve the systemic condition of patients to a certain degree and enhance the quality of life. The combination of TCM and modern medicine should be strengthened to explore the potential advantages of the synergistic treatment of DOR with Chinese and Western medicine, especially in improving fertility outcomes and delaying ovarian function decline. Moreover, emphasis should be placed on promoting the standardisation of TCM, including the whole process quality control of herbal medicines, standardisation of acupuncture protocols, and standardisation of evidence-based treatment, as well as in-depth analyses of the mechanism of action of TCM compounding with the help of modern research tools such as cyberpharmacology, histological techniques and artificial intelligence, in order to provide a strong support for the modernisation and internationalisation of TCM.

Figure 2 Shows that traditional Chinese medicine can improve the hormone level and ovarian function of DOR patients and improve the natural pregnancy rate through the mechanisms of anti-oxidation, immune regulation and signal pathway regulation through acupuncture, traditional Chinese medicine compound and active ingredients of single traditional Chinese medicine.

Although TCM faces many challenges in the treatment of DOR, its concepts of holistic management, multi-target intervention and personalised treatment provide new treatment ideas for DOR patients. In the future, it is expected to further explore the potential of TCM in the treatment of DOR and provide patients with safer and more effective treatment options, as well as laying a scientific foundation for the recognition and application of TCM worldwide.